1. Field of the Invention
The present invention relates to an X-ray computed tomographic apparatus which reconstructs an image associated with a slice of a subject to be examined, a medical imaging apparatus, and a medical image display apparatus.
2. Description of the Related Art
Slight periodic blur occurs even on an image captured by imaging a subject to be examined which is completely motionless. This is not because of image noise, but because of slight movement in the subject, which occurs, for example, at a period of 0.4 sec in a 0.4-sec scan. The causes of such blur mainly reside in mechanical variations such as the shake of a gantry due to gravity and centrifugal force and the positional shift of the tube focal position. With such variation, the position of the tube (focal point)/detector deviates from an ideal state in a cycle of 360°, resulting in the occurrence of blur on an image. In image diagnosis using still images, such blur is a level difference which is not recognized by an observer. However, in observation of a completely motionless object through a moving image, the observer recognizes the movement described above.
In an actual clinical practice, examination using an X-ray computed tomographic apparatus is considered effective in evaluating the rupture risk of a cerebral aneurysm. A cerebral aneurysm with a high rupture risk changes its shape with a change in blood pressure. Observation using moving images is therefore effective. Electrocardiographic information is electrical information generated by a change in the state of the cardiac muscle. This information also indicates a change in blood pressure to show the movement of the heart. Clarifying the association between a change in this state and a rupture risk makes it possible to properly determine the urgency of an operation and the like.